The roles of the superoxide free radical, the secondarily generated hydroxyl radical, and of the enzyme superoxide dismutase will be investigated with regard to several pathological or disease states. Particular emphasis will be directed toward elucidation of the biochemical mechanisms involved in cell-mediated inflammation, and the role of the superoxide radical in this process. BIBLIOGRAPHIC REFERENCES: McCord, J. M., Free Radicals and Inflammation: Protection of Synovial Fluid by Superoxide Dismutase, Science 185, 529 (1974); McCord, J. M., and Salin, M. L., Free Radicals and Inflammation: Studies on Superoxide-Mediated NBT Reduction by Leukocytes, in George J. Brewer (ed.), Erythrocyte Structure and Function, Alan R. Liss, New York (1975).